SAN DIEGO - Police have found the head, the hand and a suspect. Now they're looking for a motive.

Acting on a tip, investigators arrested a 61-year-old former porn shop worker yesterday in the shooting death of a homeless man whose head and hand were later dismembered.

Gerald Michael Nash was taken into custody about 5:20 a.m. at his home behind an adult bookstore that once employed him, San Diego police Lt. Jeff Sferra said.

The arrest came about two miles from where the torso of Allen Burton Hawes, 57, was found Monday in an Otay River tributary. A tow truck driver discovered Hawes' head in a plastic bag on the shoulder of Interstate 5 near the 28th Streeton-ramp a day later. Less than three hours after that, a Caltrans crew found one of Hawes' hands on the side of state Route 163.

28th Streeton-ramp a day later. Less than three hours after that, a Caltrans crew found one of Hawes' hands on the side of state Route 163.

28th Streeton-ramp a day later. Less than three hours after that, a Caltrans crew found one of Hawes' hands on the side of state Route 163.

Police and others described Nash and Hawes as acquaintances. Detectives would say little about the circumstances of the arrest or the relationship between Nash and Hawes. They stressed the investigation was still in the early stages.

Nash was arrested without incident, police Sgt. Kerry Tom said. Investigators also impounded two sedans and a van at his home. If they know, detectives are not saying when Hawes was shot or how and when he was dismembered.

Police said they knew little about Nash, whom acquaintances described as quiet and polite. Details about Hawes began to emerge yesterday, one day after his remains were identified. Hawes was an avid Boston Red Sox fan with family on the East Coast. Among San Diego's homeless community, he was well-known and well-liked.

He sometimes slept in the San Diego River bed near Old Town, a back yard in Banker's Hill and even the adult movie theater where Nash worked, acquaintances said.

Hawes collected cans and spare change, and was a familiar face at Old Town Recycling on Hancock Street. Employees there said he last came by with several bags filled with cans about a month ago.

Hancock Street. Employees there said he last came by with several bags filled with cans about a month ago.

Hancock Street. Employees there said he last came by with several bags filled with cans about a month ago.

Bill Dawdee, an acquaintance at the center, said he once shared space with Hawes in a transient encampment called Edge City, under I-5 near Mission Bay Park.

"He was no trouble. We got along in our own quiet way," Dawdee said. "Al loved the streets."

In fact, homicide Lt. Kevin Rooney said there was one constant from the many friends of Hawes' who called police to help in the investigation.

"They all said what a nice guy he was," Rooney said. Those who knew Nash said the same.

Nash until recently worked at Ever So Naughty, an adult theater and video rental store on Palm Avenue in Egger Highlands and lived in the house in the back with a roommate, who also worked at the store, said store manager Joe Bergmann.

Nash worked the graveyard shift and had been there for five years before he walked in one day in December and "up and quit," Bergmann said.

The manager said he thought Nash was a retired Air Force veteran. He described him as a quiet, intelligent man.

"He's a nice guy. It's hard for me to believe this," Bergmann said.

Nash also worked as a security guard elsewhere while he was at the adult store, Bergmann said.

Bergmann said Hawes used to come by the store about one night a week. "He would sleep in one of the seats in a small theater we have here," he said.

The store manager said he hadn't seen Nash for about two weeks nor Hawes for about a year.

At the nearby Jalisco Cafe, owner Alex Corradino said Nash came by Monday night about 8:30.

Corradino said Nash was a regular for more than 10 years. When last he stopped by, Nash "was quite calm and he ate his regular favorite dish - caldo de res - and he tipped the waitress," Corradino said.

He said Nash would usually sit in a corner and eat his meal and read a newspaper or a magazine. "He would never complain about anything."

A court search found no felonies in Nash's name.

Yesterday, Nash, hunched and limping as he was brought in to police headquarters in downtown San Diego, was taken to a hospital for a medical evaluation. Police said he would be booked on suspicion of murder.

Bergmann could not explain why Nash appeared to be limping and hunched over when he was brought to the station.